Many X-ray procedures require that the patient be moved from a horizontal resting position on an X-ray table toward an upright position to improve the radiological visibility of internal organs, increase the gravity effect on radio-opaque dye circulation, or to aid breathing, as examples. Upright inclination may be desirable only during brief radiographic exposure periods, and adjustment of the X-ray tube and its associated receptor with their radiation axis centered on a selected organ of the patient is preferably made before patient inclination and exposure. After inclination a program of several exposures at various fixed angulations of the radiation axis may be made.
It is an object of the present invention to provide an X-ray system which will allow fixing the angulation of the radiation axis between an X-ray source and receptor while a patient is in a comfortable horizontal position which maintains the fixed angulation while the patient is inclined to a more erect position, and which further allows spherical angulation of the radiation axis after inclination without changing the centering of the radiation axis on the selected organ. Spherical angulation means direction of X-radiation of an X-ray source tube from any loci on a sphere centered on the patient and an isocenter of the X-ray system. The isocenter is at the intersection of the radiation axis between the radiation source and receptor and the axis of angulation.